Question

In the first 100 elements, number of s-block elements are:
A.88
B.12
C.13
D.22

Answer 1

Hint: Take a look at the periodic table and find out the location where s-block is placed in the periodic table. The elements of s-block are also referred to as alkali metals and alkaline- earth metals.

Complete step by step answer:
As we know that in periodic table, all atoms are arranged based on their properties and the image of modern periodic table is given below as,

The first two groups on the left hand side of the periodic table are called s-blocks of the periodic table. S-block comprise alkali metals and alkaline earth metals.
The last six groups of the periodic table are understood as the p-block of the periodic table. It comprises boron family, carbon family, nitrogen family, chalcogens, halogens and inert gas elements
s-block consists of group A and group B.
The properties of s-block elements are listed below as,
1.Good conductors of both electricity and heat.
2.They are soft metals which have low melting point.
3.They are highly reactive in nature which leads to the formation of ionic compounds.
4.They are highly electropositive in nature.
Group A: it is known as alkali metals and contains lithium, sodium, potassium, rubidium, caesium, and francium.
Group B: It is known as alkaline-earth metals and contains beryllium, magnesium, calcium, strontium, barium and radium.
From the above details we can conclude that the s-block contains 13 elements including hydrogen.

Therefore, the correct option is C. .

Note: As we know that the s-block consists of the first two group of the periodic table group A and group B the elements of the first group are known as alkali metals and the elements of second group are known as alkaline-earth metals. Their oxides and hydroxides are basic in nature. Aqueous solution of their oxides and hydroxides turn red litmus paper into blue.